Regenerative repeating system



Patented June 26, 1945 UNITED STATES PATENT OFFICE REGENERATIVE REPEATING SYSTEM Louis M. Potts, Evanston, 111., assignor to Teletype Corporation, Chicago, 111., a. corporation of Delaware Application November 9, 1942, Serial No. 464,993

12 Claims.

This invention relates to signal repeaters and particularly to a repeater for regenerating signals in which the final impulse of a permutation code combination also acts as a special control im-;

for repeating signals of the start-stop variety hav- 7 ing no separate'impulse allotted for a stop impulse.

The manner of signaling employed in connection with the present invention is exemplified by the system shown in co-pending application Serial No. 334,108, filedMay 9, 1940, now Patent No. 2,323,932, granted July 13, 1943, by L. M.

, Potts. in which there is employed a five-unit Baudot-type code combination signal having, in addition to the conventional five selective impulses, a special impulse utilized for supervising secondary shift control at a start impulse interval of a polarity opposite to that of the'preoeding impulse interval. The device according to the present invention is based on the regenerative repeater shown in U. S. Patent No. 2,104,251,

moves between a pair of fixed contacts which.

are, in turn, connected, under control of the distributor shaft in the repeater, to ground when the distributor shaft is in the stop position. Upon receipt of an impulse by the repeater fromthe transmitting station, which is the reverse of the last or the fifth impulse previously received, the repeater will initiate repeating operations to carry the impulses received by it, in the transmission of the code combination, forward to the receiving staticn and thereby serve the normal purpose of a regenerative repeater. Of course, the repeater will correct the duration of impulse and the strength thereof in the well known manner. Therefore, the salient purpose of the present arrangement is to shorten the code combination so that the same fundamental signal frequency will give a higher rate in .words Der minute, or the same rate in Words per minute will give a lower fundamental signal frequency.

For a more comprehensive understanding of the present invention, reference may be had'to theaccompanying drawing and to the detailed specification following hereinafter in which similar reference characters indicate corresponding parts throughout, and in which:

Fig. l is a schematic diagram of the repeater system according to the present invention in which the signals are of conventional length, but

in which a sixth impulse is incorporated with the I stop interval and the start impulse is varied to contrast with the stop impulse;

Fig. 2 is a diagrammatic chart of a code sig-- nal such as may be used in the system disclosed in Fig. 1, showing .how its component parts are functionally allocated; and

Fig. 3 is a. side eleva-tional view of the stop gate control mechanism.

Referringto Fig. 1, line wire I connectsa transmitting substation indicated generally as 2, and a repeating station 3 comprising a signal receiving magnet '4 in a controlling circuit. Repeating meansis positioned between magnet 4 and a receiving station 5, and line wire 6 connects the repeating station with the receiving station.

Whereas conventional five-unit permutation of either one oftwo alternative current condi tions.

In the incorporation of, this plan of operation, it has been found expedient to utilize plus and minus current conditions to represent marking and spacing, instead of the conventional practice of utilizing current and no current conditions for this purpose. Moreover, there will be utilized for the purpose of signal translation, a six-feeler testing apparatus generally indicated by the reference character 1. Feeler mechanism 1 is illustrated as having seven contaotors 8 to M, inclusive; however, contaotors I3 and I 4 are both carried upon a single feeler lever while each of the remaining contactors 8 to l2, inclusive, is carried individually upon a feeler lever.

In accordance with the operation of its feeler lever, each contactor is spring urged so that it will engage the contact block toward the right (as viewed in Fig. 1) and is capable of movement in an opposite direction so as to engage the contact block towards the left, as illustrated in Fig. 1. The contact block at the right is comprised of a large section indicated I5, and a smaller section, insulated therefrom, indicated IS. The contact block at the left is similarly comprised of two sections, the larger one indicated l1, and the smaller one indicated l8. Moreover, as may be noted, the small contact block I8 is connected electrically over an obvious line with the large block I5, and correspondingly, small contact block I6 is connected electrically with the large contact block ll. Opposite sources of grounded battery or potential indicated I9 and 2| are connected, respectively, to the contact blocks I8 and I6 and over lines 22 and 23 to the oppositely placed contact points of armature 24 under the control of a polar relay 25.

One terminal of relay 25 is connected to the afore-described contactor l4 and the other to a distributor segment 28, located in the distributor ring 21. The distributor 28 which includes, also, distributor rings 29, 3|, and 32 is of the startstop type having a brush carrier 33, which supports two pairs of bridging Wipers or brushes 34 and 35. Brush carrier 33 of transmitting distributor 28, is conventionally illustrated in Fig. 1, but it is to be understood that this element is driven through a friction coupling, preferably in a rotary direction that it may be restrained from movement by the intervention of an armature 36 under the control of a start magnet 31. Also, the pair of wipers 34 serve to connect segmented distributor ring 23 with the solid distributor ring 3| which is electrically connected to the line conductor and that the pair of wipers 35 correspondingly connect distributor ring 21 which contains the segment 26 previously described, with the grounded distributor ring 32.

Reference will now be had to distributor ring 28 which, as will be seen in Fig. 1, is made up of seven segments. When the brush carrier 28 is in its arrested position, Wiper 34 is contacting the slightly longer segment designated 5 in the distributor ring 29. Also, it may be observed that following the segment 5, which serves also in the capacity of a stop segment as will be later described, there is encountered a start segment designated by the character S.

Following this segment is a segment designated 0 (zero), which has been arbitrarily assigned to the function of controlling the secondary shift which is fully described in co-pending application Serial No. 334,108 previously mentioned. This control is otherwise executed, in accordance with the present embodiment in a manner generally similar to that described in connection with the disclosure of said co-pending application. The remaining segments 2, 3, etc.,

including segment 5 (which, as has already'been stated, functions in a dual capacity), serve to distribute those signal impulses which relate to the composition of the permutation code. Segment 5 is connected over a conductor 38 to the contactor |3. Segment S is connected over a conductor 39 to the armature 24 of polar relay 25. In Fig. 1 is illustrated diagrammatically, transmitting station equipment including a perforated tape controlled mechanism and a rotary signal transmitter under the supervision thereof for issuing signals of a type adapted to exercise the control function including primary and secondary shift supervision of printing apparatus having mechanically the characteristics exemplified in the showing of Fig. 11 of the co-pending application, Serial No. 334,108 which is diagrammatically shown in the box portion 5 of Fig. 1 of the present disclosure.

As the brush carrier 33 proceeds in the downward direction as indicated by the arrow 40, the pair of wipers 34 leave segment No. 5 and encounter segment S, bridging this element of distributor ring 29 with the solid ring 3|. Assuming for the sake of illustration, that the perforated tape signal which has just been positioned and which has been impressed upon the feeler levers of record reader 1 is such that contactors l3 and 4 (which operate in unison) are moved to the right, that is to say, with contactor |3 engaging block l5, and-contactor |4 engaging block l6, distributor segment No. 5 will have received positive current potential from grounded battery l9 over conductor 38. This circuit is traceable from positive battery l8, segment l8 to segment l5, contactor l3, conductor 38, segment No. 5 of distributor ring 28, brushes 34 to outgoing conductor segment or ring 3| which is grounded at the repeating station 3. As the brushes proceed to the next segment which is designated S, opposite polarity is issued from grounded battery 2| as polar relay 25, in accordance with its preceding operation, has been left in a position whereat its armature 24 engaged the contactor of conductor 23. This circuit is traceable from negative battery 2|, conductor 23, armature 24, conductor 39, segment S of distributor ring 29, brushes 34 to line ring 3|.

If instead of the supposed example described above, the particular signal had been one in which the feeler lever with which contactors l3 and H are integrally associated was positioned to the left causing engagement with contact block I! and I8 instead of contact block l5 and Hi, the electrical characteristics relative to segment 5 and S would be opposite to that just described. With the brushes 34 passing over segment 5, negative potential would be supplied from grounded battery 2|, segment "5, segment contactor l3, over conductor 38 to segment 5. Likewise, positive current would be supplied from grounded battery l9, conductor 22, armature 24 of polar relay 25, which has been energized to its opposite position, conductor 39 to segment S of distributor ring 23. Each of the feeler contactors 8 to |2, inclusive, is connected over an individual conductor with an associatesegment 0 (zero) to 4 of the transmitting distributor ring 38. Accordingly, when a feeler lever encounters a perforated position in the tape, its contactor will be moved into one position, say the right-hand one (Fig. 1), engaging the contact block l5; while if said feeler lever encounters a nonperforated position, its contactor will assume an opposite condition; that is, contacting the opposite block H. The designation of positive or minus signals to correspond with perforated or non-perforated signal components is arbitrary, and is to be understood that the reverse association is equally practicable.

Not only is the foregoing true of the five feeler levers associated with contactors 8 to I2, inclusive, but also of the special feeler lever associated with contactors l3 and I4. In the case of the spe cial or ixth feeler lever, however, when a perforation is sensed, and both contactors are moved to the right, contactor M will be introducing negative current from battery source 2| to the winding of polar relay 25,-wh'ile contactor 13 will be introducing positive battery from source!!! over conductor 38 to the stop segment 5. Conversely, with the contactors i3 and 14 in theopposite'position, that is, engaging contact blocks I1 and I8, positive current originating from source l9 will be impressed through contactor H to the winding of bias polar relay 25, while negative current from source 2| will be introduced over conductor 38 to the stop segment 5. Accordingly, since armature 24 of relay 25 is connected to the start segment S, the result of the operation of the sixth or special feeler lever will be understoodas one controlling the reversal of current for start segment S; that is to say, with a given condition on the part of segment which may be either plus or minus, the sixth feeler lever controlling contactors l3 and I4 operates to provide an opposite current potential to the start segment S.

The purpose of having provided polar relay 25 with itsarmature 24 connecting plus or minus current to the segment S instead of directly connecting the contactor 14 to said segment-S is to permit the start impulse signal interval to be stored. The transmitter utilized is'of the wellknown magnet type wherein a new signal is sensed during the start interval. If a new signal should be sensed which would cause the contactors l3 and 14 to move to their opposite position, the start impulse would be of the same polarity as the stop impulse. However, by providing the polar relay 25 the armature 24 thereof will be held in a position whereby potential opposite to that of the stop segment 5 will be assured, as the armature 24 retains such position until the brushes 34 have passed the start segments, or

until brushes35 sweep across segment 26 of ring 2! thus providing a grounded circuit for the polar relay 25. At this time the armature 24 may move to the opposite side if the contactors Hand [4 have moved, but the start impulse has already been transmitted.

In Fig. 1, the reference character 5 designates a receiving station and within said outline are'contained the symbols representing important'apparatus responsive to the signal generated by the transmitting distributor 28. However, intermediate the transmitting station 2 and the receiving stationfi is the repeating station 3 whereby the signals are repeated with renewed strength and form. The line wire I extending from the transmitting station is connected at the repeating station 3 to the polar relay 4| and then to ground. The armature 42 of relay 4| is connected over 'conductor 43 to the receiving relay 4 at the repeating station, and then through battery 44 to ground. Receiving magnet 4 controls, through mechanism hereinafter described, a pair of retransmitting contacts45 and 46 connected tobatteries 41 and 48 respectively. The retransmitting contacts 45 and 46 serve to connect the associated batteries 41 and 48 over conductor 6 to the polar relay 5! at the receiving station 5.

Magnet 4 has an armature 52 pivoted to a supporting frame bypivot 53. A retractile spring 54 attached to an arm 55 of lever 52 tends to bias lever 52 counterclockwise. Extension 55 constitutes a follower for a six-tooth cam 55 fixed to a cam sleeve 5! which is sleeved upon a continuous- 1y rotating power shaft 58; A retransmitting member BI is pivoted to the frame by pivot 53 and terminates in a thin flat edge which cooperates with a locking bell crank leverBZ. Member BI is supported between arms 52 and "55 by compression springs 83 and 64. The member BI is positioned positively by engagement between the thin edge of member 6| and a confronting'thin edge or a locking bell crank lever 62 which is pivoted'to the frame at 65 and is biased in a clockwise direction by a spring 65, and constitutes a follower for a seven-tooth cam 61 which is fixed withcam 58 upon cam sleeve51. Carried on the retransmitting member BI is a retransmitting tongue 58 which carries on its end, and insulated therefrom, contact members-H and 12. Contact member H operates between the aforementioned contacts 45 and 46, in a manner to be hereinafter described, to control the retransmission of signal impulses from the repeating apparatus. Contact member 12 operates between a pair of contacts 13 and 14, as will presently appear.

Power shaft 58, besides carrying the cams 5B and 61 also carries a stop arm 15. which engages a gate 16 pivoted at ll upon a member l8. 16 is restrained by a latch19 (Fig. 3) pivoted at 8| upon thememberlB and ten'sioned bya compression spring 82 extending from latch 19 to member. Extending'betwen latch I9 and the armature-52 of magnet4 is a start lever 83, pivotcd to the frame at 84 and engaging at the end ofits horizontal arm a'plunger 85 slidable in frame part 86 and engaging at its upper end a projection on armature 52. Also mounted on shaft 58 is a cam 81, which cooperates with a follower. of 88 integral with stop gate "to actuate said stop gate at the end of each revolution of shaft 58, so that said stopgate 16 will be invariably held on the stop position at the end of each s gnal, and the stop arm 75 will invariably engage said stop gate'TB regardless of the position of the armature 52 at that time. Also mounted on the shaft 58 is a cam 83 which is adapted to operate a set of contacts 9I and 92 in the stop position of the selector shaft 58. The cam 89 operates upon contact tongue 93, in turn; to close the con tact 9! or 92 to ground.

. The operation of the regenerative repeater ='3 will now be described. For the purposes of the present description it will be assumed that battery l3 of the transmitter 2 supplies marking current to the signal line, conductor l and the battery 2! supplies spacing current thereto. The condition of the system as shown in Fig. 1 is that of rest or idleness of the line with the'co'ntact Zllopen and the magnet 31 tie-energized so that armature 36 is released to hold the distributor arm 28 against rotation, thus maintaining brushes 34 in engagement with the No.5 segment, which according to the present invention is substituted for the customarily independent stop segment which has been omitted and consequently merged into the No. 5 segment. It is thus seen that the stop impulse will be of marking or spacing nature dependent upon the nature of the No. 5 impulse of thelast transmitted code or combination. The arrangement as shown in Fig. l is such that the last transmitted impulse for the No. 5 interval is of marking naturefrom battery l9 so that the current of marking'nature is conducted over the line conductor 1 through the windings of the polar relay 4! of the regenerative repeater at station 3. Thus the armature 42 of the polar relay dl is held to the marking side (as shown), thus closing contact 95 thereof, and opening contact 96.

The operating shaft 58 of the repeater is shown with the cams thereon in the stop positiomwith the stop gate 16 acting to prevent the'rotation Gate conductor 99, through contact 92 and over contact tongue 93 to ground. I

Now, if the stop current onthe line 1s of spacing nature instead of marking nature as .justdescribed, then spacing current will be impressed on the line conductor I from battery 2| over the circuit previously described to energize the polar relay 4| in such a manner as to swing its armature 42 to close its contact 96 and open its contact 95. Then, as will presently appear, the arm 6| will have assumed the position on its spacing side, which is opposite to that shown in Fig. 1 so as to bring the contact tongue 12 into contact with lower contact 14, thus completing an energizing circuit for the receiving magnet from battery 44, through the winding of magnet 4, over conductor 43, through armature 42 and contact 96, over conductor |8|, through contact 74, over contact tongue 12, over conductor 99, through contact 92, and then over contact tongue 93 to ground. As previously described, the contact 92 is closed only during the stop interval, and during the remaining signal impulse intervals contact 9| is closed, and contact 92 remains open, so that the energizing circuit for magnet 4 becomes independent of the contacts 13 and 14, as will presently appear.

Upon de-energization of magnet 4, armature 52 will be released, permitting the cam follower 55 to drop into the path of the six-tooth cam 56 and permitting the armature extension 52 to push the plunger 85, which will operate lever 83 to cause the operation, in turn, of latch 19 which will release the gate 16 to permit stop arm 15 to escape and thus permit the rotation of the cam sleeve 51 and the cams 56, 61, 81 and 89 thereon, by the power of shaft 58, through the instrumentality of, a friction clutch (not shown). released by'the de-energized magnet 4, also compresses spring'63 (since spring 54 is stronger than spring 63) and releases spring 64, but transmitting element 6| resists the spring pressure because it is still locked by locking lever 62, which is in the path of the seven-tooth cam 61, which cam now is starting to rotate. The first mechanical action of the cam sleeve and its cams is to operate the lock lever 62 counterclockwise by cam 61, thereby releasing member 6|, which moves tongue H from contact 45 to contact 46, and tongue 12 from contact 13 to contact 14. The movement of the contact tongue II from contact 45 to contact 46 causes the Operation of armature 52, when 'lever' 62 leaves 'the 'end' of member 6|. "The impulse from station 2, which now is repeated to station 5, thus has been determined in point of time solely by the movement of cam 61 acting through lever 62 to release member 6|, but has" been determined as to electrical -nature, solely'by the position of armature 52 which has been controlled solely by the signal received in magnet 4 under the control of station 2.

As the cam sleeve 51 begins to rotate, the projection of cam 89 fixed to said sleeve passes out of engagement with the contactor 93 so that said contactor will operate to open contact 92 and close contact 9|. Contact 92 remains open and contact 9| remains closed, therefore, during the continuance of the entire cycle, except for a portion of the No. 5 impulse interval. Thus it will be noted that at the end of'each cycle, commencing with-the last portion of the No. 5 impulse intervahcontact 92 will be closed and the magnet 4 may be energized'either in response to marking or spacing signals, as previously described, over the circuits including contacts 95 and 96, and I4 and l3, respectively, for marking and spacing.

'However, during'the remaining portion of the cycle when contact 9I is closed, the contacts 13 and" are ineffective, and the magnet 4 will respond only to marking impulses, the spacing impulses causing said magnet'to become de-energized in the manner well known in the art.

Cam 81, as previously described, operates upon the follower arm 68 integral with the gate 16. In the stop position of the sleeve 51, the high portion of the cam 8! assumes the position shown in the Fig. 1, just having passed the projecting portion 88 so thatupon the receipt of the start impulse, the magnet 4 will become de-energized and latch 19 will be disengaged from the gate 16, permitting the stop arm 15, under the influence of the friction clutch connection to shaft 56, to rotate the gate 16, the cam 81 notat this time preventing movement of the arm 86. However, near theend of the cycle of rotation of sleeve 51 the high portion on cam 81 cooperates with the arm 88 so as to rotate the stop gate 16 in a counterclockwise direction to bring the stop portion of the stop gate I6 into the path of the stop arm 15, regardless of the state of energization or de-energization of the magnet 4, thus invariably causing the stop arm 15 to engage the gate 16 for stop purposes, since as previously described the stop impulse may be of marking or spacing nature, corresponding to the nature of the N o. 5 signal impulse of which it is a part.

Referring again to the cycle of events during the rotation of the cam sleeve 51, the next step following initiation of rotation is the engagement of a tooth of cam 56 with its follower arm 55, whereby armature 52 is moved toward or against its controlling magnet 4. This action occurs six times in each cycle, each such occurrence at about the middle of each of six of the signal to be repeated from the transmitting station 2 to the receiving station 5, the repeated signal effecting the polar relay 5| in a manner to be hereinafter described. The operation of locking lever 62 is momentary because of the short arcuate dimension of the teeth of cam 61, and member 6| immediately is relocked. In operating to unlock the member 6|, locking lever 62 permits no movement of member 6| while the flat side of its thin edge is in engagement with member 6|, the release of member 6| being made suddenly at the instant when the end of code signal impulses; namely, zero, first, second, third, fourth, and fifth, intelligence signals (the fifth signal including also the stop signal of the code). In each instance, armature 52 will be held by the magnetism of energized magnet 4 if the instant signal, being a marking signal, operates to energize the magnet 4; but in each instance, armature 52 will be released by the passing of a tooth on the cam 56 by the follower arm 55 if the signal impulse is of spacing nature. In every such occurrence, actuation of follower 55 by cam 56, and the retention or release of armature 52 by magnet 4 will be followed imme diately by the operation of the lock lever 62 by cam 67, which will permit member 6| to operate the contact tongues H and I2 into'engagement with their respective contacts depending upon whether the magnet 4 has retained armature 52 and has compressed spring 64, urging member GI upwardly when unlocked by lever 62; or has ro leased armature 5,2 and has compressed spring 63, urging member 6! downwardly when released by lever 62.

In prior structures, in each code group. of im pulses, a final impulse or a stop impulse is. provided which is independent of the intelligence co e impulse and s always of m rkin charac teristics, thereby attracting the armature 52. However, in accordance with the present invention, the independent stop interval has heenomited and h be incorporat d n he ode nal interv l, said No.15. impu se function n dual y s a signaling im ulse and a stop impulse, u ng he ime aid No. 5 impul func ion as s op impulse, the ea n, 89 acts n the c n ac tong e 93 t close the con act 92 to r nd r the agnet 4 re pons e. to s nals f ei her mar in or spacin nature, depen n upon then ture o the No. 5 impulse in rva Th contact .2 is closed only f er the fifth impuls pe iorrned its selecting fu ct on. From the fore oin the it will be noted that if contact 82 isolosed, the magn t; 4 will be n rgized w ether he No. 5 signal impulse was marking or spacing, The ontact 92 is closed nly durin e nt r al that the fif h impulse fun tions as s op mpulse because the complementary interval of said im-. p lse is utilized for s g l n pur oses. Thus a portion oi the fifth impulse is utilized for stop p rp s s on y. n l eu of h ua i dependen stop interval.

In the description of operation of'the transmitt ne a d repeating stat ons it is assumed, o course, that the distributor arm 28 rotates in synchronism with the cam sleeve 51. It will be further assumed that the rus es are Just entering upon contactual engagement with the No. 5 impulse segment, Accordingly since. the cam sleeve 51 is in synchronism with the transmitting r butor, the h g portion f cam 8 s appreaching the contact tongue 93 which now is in contactual engagement with contact 9|. In this condition of the circuit and apparatus, if the fifth signal impulse s marking, then th o tact tongue 42 of polar relay 4| will be biased so as to close contact 95, and the energizing circuit for magnet 4 will be closed over the following circuit: From battery 44, through the winding of magnet ver conductor 3, and ver contac tongue 42, through contact 95, over conductors 91 and I02, through contact 9] and over contact tongue '93 to ground. It will be noted that, in response o a marking s gnal the armatu e 5.2 will be attract d, and t e member 61 ll be operated to the marking side, which will close contacts 45 and 73. NOW, since the No. 5 impulse is ma g as the cam 89 reaches the contact tongue 93 and operates said. tongue to close ontact 92, the magnet 4 will still remain energized, but over the ir u t e t nding m tte y 44, through the winding of masnetd, over con cluste 3, t ugh contact ongue 2, h ou h contact 95, over conductors '9 and 9.8, through ntact 13, over tongue '12 and o er onduct 99, through conta t .92 and over cont t ton ue 93 to ground.

On the t e hand. let it he assumed that th No. 5 s gnal impulse is o spa ing nature a d, as-

same a a n that he. cam, 8.9 is. in. a position where its projection has not yet reached the contact ton ue 93 dur n the No: 5. impulse interval- Then contact 51 will he closed, but the contact tongue 42 of polarv relay 4| will be in engagement with the spac n contact 86, h eupon the magnet 4 will become de=enereized since the energizing circuit therefore has been broken atcontact 82. In ponse to the spaci si na however, the mailnet 4 becomes tie-energized and the armature 52 i r ease hus the member 6! will assume its h e s on. s pr iously d scribed. to close contacts and 14. Then, when the high portion of cam 89 cooperates with the contact tongue 93 to close contact 92, the magnets will bec me energized over a circuit extendin from atte y 44, through the winding of magnet 4, over conductor 43, through contact ton ue 42 and contaet r onductor ,lul, throu h contact 14 over contact tongue 12, over conductor 99, throu h contact 92 and over contact tongue 93 to ground. It is thus seen that the magnet A will become energized during the time interval that the No. 5 impulse functions as a. stop impu se re ardless of W eth r t e impulse is of markin on spacin nature.

From the previous description it will be. noted that the impulse following the No. 5 impulse, which is the start impulse, is always of an elec. trical characteristicor nature opposite to the nature or characteristic of the No. 5 impulse so as to cause the de-enereization of the receiving m net, ither by pacing or m rkin urr nt. In the prior structure the markin current designated the stop interval, andthe start interval was always of a spacing nature. In accordance with .the present invention, wherein the nature of th start current is determined by the nature or the current of the No. 5 impulse, it is seen that the stopping current may be of either nature, and

hence the starting current must .be the reverse nature. It will be noted thatv regardless of whether the magnet 4 has been energized in-the pr vi s'ooole cycle by a ma ing or spacing si nal, the start signal impulse being of QDDOsite nature will cau ethe armature 42 of polar relay 4| to swing totheopposite contact, thus breaking the previous energizing circuit forthe ma net 4, as previously described, therebycausing the mags net 4 to become deeenergized and the cam sleeve 51 to rotate by the operation of plun er 8.5.125 armature 52, and consequently the operation of the. retrensmittlpg contacts .5 and, 45 to liect he re t tion of he si na and t nsmissi n thereof o er line l v As p e ousl ent one the re eren e character 5 nd cates a recei ing sta io ha in ee nev a paratus of the typ discl sed in o pen ins appli a ion Se ial No,- 334,, 08, and which. for the purpos s. of theprese t d closu will be ie ly described. Th r ference ha cter ndicates a po ar relay having an a ture 5 h ch res oates between two co t t Points 1116 an ml which are part of a local circuit for on roll ng the operation oi the receivin magne I98. Also located in the receiving station 5 are a Pair of n a rs ns ioeteo 9 and l o tactor "l eoi ro at s betwe n a pai o onta t points I I2 and I I3, and the contactor H l operates between a pair of contact points HI and H5. Contactor I09 is operated by a special cam carried on the selector cam sleeve of a printer of the type shown in U. S. Patent No. 2,247,408,

issued .July 1, 19.41, to Beiber, and this cam isanalogous to cam 89 of the regenerative repeater mechanism at therepeating station 3.. Thus, contactor I09 and its associated contacts IIZand II 3 correspond in function to contactor- 93 and contacts 9I and 92, respectively, of the repeating mechanism. Also, contactor I05 and its associated contacts I06 and I01, correspond with and are analogous to contact tongues 12 and I4, respectively.

Briefly stated, armature I05 of relay5i fluctuates in accordance with the signal impulses transmitted over the line 6 from the repeating station 3, and contactor I09, being controlled by a cam apex on the selector cam sleeve, rests against contact point .I I2 at all times except during the stop and start signal interval. Also, contactor III being controlled by the No. 5 signal is moved into one or the other of two alternative positions as a result of the operation of the transfer. mechanism only during the period corresponding to this impulse. More specifically,.the contactor I09 rests against the-contact II3 only during the latter portionof the No. .5 impulse interval in the manner as similarly described in the case of the repeating mechanism shown in the repeating station 3. Under an assumed set'of conditions, for example, in response to marking signals, both contactors I05 and III will be deflected so as to engage their contact points I06 and I I4 respectively, while in response to spacing signal impulses, said armatures or contactors I05 and III will be in their opposite-position, that is, engaging respectively their contact points I01 and H5. Also, it is to be recalled that since the No. 5 impulse functions in the dual capacity of effecting the distributor stop control as well as entering into the permutation code, each signal must be considered with reference to the No. 5 impulse of.

the preceding signal which affects the current characteristics of the start impulse as well as of the concluding No. 5 impulse, because it, together with-impulses Nos. I, 2, 3, and 4, comprises the code combination of the particular signal.

Accordingly, when the No. 5 impulse of a preceding signal happens tobe marking, armature I05 will be thrust into engagement with its contact point I06, contactor I09 will be permitted to engage its contact point I.I2 (on account of the operation. of the cam on the selector sleeve), and contactor I I I, as a result of a, transfer operation, as clearly described in the aforementioned patent, will be moved into engagement with its contact point II4. This will complete a circuit traceable from grounded battery II6 through the winding of magnet I08, over contactor III, through con-- tact I I4 (with which it is now in engagement), conductor II'I, contact I05, and contactor I05 to ground. As a result of the continued energization of magnet I08 its armature is held, and the rotation of the selector cam sleeve is arrested in accordance with the conventional operation of printing telegraph selector shafts. This condition continues until the circuit for energizing the magnet I08 is broken, which change occurs upon the receipt of a proper start impulse over segment S,

of the transmitter 2 and repeated over the contact 46 or 45 of the repeater 3. The polarity of the start signal being opposite to that of the No. 5 or stop signal impulse, as already explained, causes armature- !05 of polar magnet 5| to be moved to engage its contact point I01 and away from its contact point I06. This interrupts or opens the circuit for magnet I08, causing the release of its armature and consequently initiates the rotation of the receiving distributor cam sleeve shaft in a manner clearly described in the Reiber Patent 2,247,408.

As the distributor shaft or cam sleeve of the printer mechanism, indicated at the receiving station 5, rotates, the cam apex controlling the contactor I09, rides off the contactor I09 permit-. ting contactor I09 to be drawn away from its contact point H3 and to come into engagement instead with its contact point II2. Meanwhile contactor III remains in engagement with its contact point II4 because it can be changed only during the fifth impulse interval. As a result of the change in contactor I09 from contact point II3 to contact point IIZ, no effect is obtained at this time, because magnet I08 continues to be deenergized until, during the course of the six signal impulse intervals, 0, I, 2, 3, 4 and 5, and armature I05 in response to itsrelay 5I returns to engage its contact point I06, which response can-occur only under the control of marking signal impulses. If the signal impulse corresponding to the No. 5 interval is of spacing nature, then contactor I05 will be swung over to the contact I01 and thereby open contact I06. As a result of this selection, contactor III will engage its upper contact point II5 instead of the lower contact point I I4, while (because of the cam apex on the special cam previously mentioned) contactor I09 will again be operated against contact point II3. Thus, a circuit will be completed for energizing the magnet I08 extending from grounded battery II6, through the winding of magnet I08, over contactor III, through contact II5, over conductor II8, over contactor I09, through contact II3, over conductor I I9, through contact I01, and over contactor I05 to ground.

As a result, magnet I00 is held energized, which is the proper condition corresponding to a stop impulse,- until an opposite current condition is received by the relay 5I, causing its armature I05 to be withdrawn from contact point I01 and to engage instead the contact point I06. When this occurs, contactor I09 is still held against its contact I I3 because of the function of the special cam on the selector sleeve (which is analogous to the function of cam 09 of the repeating station 3 upon the contactor 93), which maintains said condition during the interval corresponding to the start impulse. Meanwhile, the last described movement of armature I05 causes the energizing circuit for magnet I09 to be broken, and accordingly releasing its armature for the purpose of initiating rotation of the receiving selector cam sleeve or shaft as previously described. Thereafter, and coincident with the 0 (zero) signal interval, contactor I09 is restored to its condition which prevailed during the longest portion of the cycle; that is, engaging its contact II 2. When this occurs, that is, when armature I05 of relay 5I engages contact point I06, marking impulses are thereafter interpreted as magnet I00 energizing impulses, because contactor III continues in engagement with its contact point II5, causing the magnet I08 energizing circuit to be completed over the following described circuit: From grounded battery I I6, through the winding of magnet I08, contactorIII, contact II 5, con ductor IIO, contactor I09, contact II2, conductors I2I and 1, contact I06, contactor'l 05 to ground. Thus, phasing of the receiving magnet I08 as well as its controlled distributor or selector shaft is regulated, notwithstanding the reversed conditions of the No. 5 and start impulses;

From the foregoing description it is observed that a regenerative repeater has beenprovided notedthat, although in Fig. 2 the fifth impulseinterval is indicated as being. somewhat longer than the other impulse intervals, it is, to be understood that such relation is not essential to the successful operation of the arrangement disclosed .herein, but is merely so shown since in existing start-stop signalling systems the normal stop period or interval is slightly longer than the:

remaining impulse intervals.

While the arrangement disclosed in the drawing has been explained and described with ref-,

erence to specificembodiments, it is not intended to be restricted in any manner to the language of the detailed specification nor to the illustrations in the accompanying drawing, except as indicated in the hereunto appended claims.

What is claimed is:

1. In a telegraph repeater, sive to current impulses for releasing -atiming cam sleeve for rotation, a contact member for retransmitting a received signal, an armature controlled by a received signal, a spring tensioned by said armature and acting to urge said contact member to an alternative position, a locking member restraining said contact member, said timing cam sleeve operating said locking member to release said contact member to control the timing of a retransmitted signal, a receiving line relay having an armature responsive to alternative line current conditions, two electrical circuits including said line relay armature and said magnet, a principal switch efiective in response to the final impulse of a series of impulses comprising a signal to prepare one or the other of said two circuits to said magnet, and a shunting switch effective during certain other intervals only of said series of impulses for shunting one of said circuits.

2. In a telegraphic repeating device, a contact member for retransmitting a received signal, an armature controlled by a received signal, a spring tensioned by said armature and acting to urge said contact member to an alternative position, a locking member restraining said contact member, a timing cam operating said locking member to release said contact member to control timing of a retransmitted signal, a receiving line relay having an armature responsive to alternative line current conditions, two electrical circuits including said line relay armature and said magnet, a principal switch responsive to the final impulse of a series of impulses comprising a signal to prepare one or the other of said two circuits to said magnet, and a shunting switch effective during certain other intervals only of said series of impulses for shunting one of said circuits.

3. In a telegraph repeating apparatus, a signal controlled magnet, a line relay having an armature responsive alternatively in accordance with two different received line signal impulse conditions, a pair or electrical circuits communicable with said line relay armature for establishing connection with said receiving magnet, a cona magnet resl flntactor effective in accordance with theresponse. of said magnet to said line signal impulse icondi tionsv for selecting one. or the other of said two circuits, meansfor timing the operation'of said contactonand means effective during an initial, period ,of each signal for shuntingrone ofsaid' circuits to render said magnet normallyresponsive'to only one of said line signal conditions, said meanseffectivevduring a final period of each signal to rendersaid magnet responsive toeither; line signal condition, whereby said magnetwill invariably be rendered unenergized in response to the next contiguous impulse irrespective :of its line condition. v

4;: In a telegraph repeating, apparatus, a signal controlled magnet, an armature for said magnet, retransmitting contacts, centralized .means associatedwith said armature and responsive thereto for operating saidfcontacts to effect-the regene. erationof repeated signals, means. for assisting saidarmature, means for timing the response of said, centralized means tothe .movements of said .armature,- av polar line, relayl. responsivetoalternative line current conditions, said, relay, .having an armature, two electrical circuits connecting said line relay armature with said, mag-- net, a principal switch carried by said centralized; means responsive to the final impulse of a series of impulsescomprising a signal for. preparing one of said two, circuit paths to;saidmagnet. anda:

shunting switch efiective during certain other.

intervals only ofsaid series of impulses for, shunting one of said circuits.

5. In a telegraph repeating apparatus, a signal controlled magnet, an armature for said magnet, retransmitting contacts, centralized means associated with said armature and responsive thereto for operating said contacts to eiTect the regeneration of repeated signals, a cam assembly, a cam in said assembly effective for assisting said armature, a further cam in said assembly for timing the response of said centralized means to the movements of said armature, a line relay responsive to alternative line current conditions, said relay having an armature, two electrical circuits connecting said line relay armature with said magnet, a principal switch carried by said centralized means for selectively preparing said circuit paths to said magnet, and a shun-ting switch controlled by a cam in said assembly effective during certain signaling intervals for shunting one of said circuits.

6. In a regenerative repeater, signal timing means quiescent during non-signalling periods, means to initiate said means into operation at the beginning of each signal, a magnet to control the initiating means, a plurality of energizing circuits for said magnet, a principal switch'for selectively preparing said circuit paths to said magnet, and a shunting switch controlled by said signal timing means effective during certain signaling intervals for shunting one of said circuits.

'7. In a telegraph system, means to transmit equal length permutation start-stop code signals, timing cams started into rotation at the beginning of each signal, signal retransmitting means timed in operation by said timing cams, means governed by said timing cams to control the spacing or marking nature of each element of the signal by the nature of the corresponding element of said original signals, means to stop the motion of the timing cams at the end of a sigand means controlled by certain of said cams to restart said timing cams only when the nature of the line current changes.

8. In a regenerative repeater, a line relay responsiveto incoming signals, means to simultaneously generate two sets of signals under control of said line relay comprising a plurality of pairs of contacts, contact operating means therefor, and signal controlled means for controlling the operation of said contact operating means, and means comprising a shunting switch also controlled by said signal controlled means to invert some only of the elements in one of the sets of signals.

9. In a regenerative repeater, a line relay responsive to incoming signals, means to simultaneously generate two sets of permutation code signals under control of said line relay comprising a plurality of pairs of contacts, contact operating means therefor, 4 means for controlling the operation of said contact operating means whereby at least one of the elements of one of said sets of signals is adapted to control dual functions, and means comprising a shunting switch also controlled by said signal controlled means for causing said element to control phasing operations of the repeater.

10. In a regenerative repeater, signal timing cams quiescent during non-signalling periods, means to initiate said cams into operation at the beginning of each signal, each of said signals comprising at least one element having dual funcand signal controlled,

tionary characteristics, a magnet to control the initiating means, a plurality of energizing circuits for said magnet, and switching means controlled by certain of said cams to determine the energizing circuit for said magnet.

11. In a telegraph system, means to transmit equal length permutation start-stop code signals, each signal comprising at least one impulse element having dual iunctionary characteristics, a

, cam means started into operation at the beginning of each signal, signal retransmitting means timed in operation by said cam means, means comprising a shunting switch controlled by said cam means to control the functionary characteristics of said element, means to stop the motion of the cam means at the end of a signal independent of the characteristic of said element, and means controlled'by said switch to restart the cam means only when the characteristic of the line current changes.

12. In a regenerative repeater, a timing instrumentality, means acting at the beginning of each received signal to start the timing instrumentality into operation, means controlled by the last impulse of a signal to determine the character of the corresponding impulse in the regenerated signal, a shunting switch, and means acting on said switch subsequently to said determining 'means to condition the starting means regardless of the character of the last impulse of the signal received.

LOUIS M. POTTS. 

